Generally speaking, yes, cash games are typically more profitable and are usually easier to actually BE a winning player at. Single-table SnGs (STTs) are probably the hardest form to be continually profitable at. You can expect huge swings and will need to study tons and tons to ever move-up from the very lowest stakes and still remain profitable. Having said all that, I do play them from time-to-time simply because I enjoy them.
That's not something that should be underestimated, imo. If you enjoy them more, and are therefore willing to put in lots more effort than you would studying cash; then they may be the best way for you. But, for most people, cash is simply easier to be routinely profitable at. Another option that you may consider is Multi-table SnGs, or just regular MTTs, but I have little experience in those, so I really don't want to advise you one way or another on that.